title: Heterologous expression of Lactobacillus casei RecO improved the multiple-stress tolerance and lactic acid production in Lactococcus lactis NZ9000 during salt stress.
abstract: The aim of this study was to investigate the effect of nisin-inducible RecO expression on the stress tolerance of Lactococcus lactis NZ9000. RecO protein from Lactobacillus casei Zhang was introduced into Lactococcus lactis NZ9000 by using a nisin-inducible expression system. The recombinant strain (NZ-RecO) exhibited higher growth performances and survival rate compared with the control strain (NZ-Vector) under stress conditions. In addition, the NZ-RecO strain exhibited 1.37-, 1.41-, and 1.42-fold higher biomass, lactate production, lactate productivity, compared with the corresponding values for NZ-Vector during NaCl-stressed condition. Analysis of lactate dehydrogenase (LDH) activity showed that the production of RecO maintained the stability of LDH during salt stress. These results suggest that overproduction of RecO improved the multiple-stress tolerance and lactic acid production in Lactococcus lactis NZ9000 during salt stress. Results presented in this study may help to enhance the industrial utility of lactic acid bacteria.
authors.affiliation: Key Laboratory for Leather Chemistry and Engineering, Ministry of Education, College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu 610065, PR China.
authors.forename: Chongde
authors.initials: C
authors.lastname: Wu
authors.forename: Juan
authors.initials: J
authors.lastname: Zhang
authors.forename: Guocheng
authors.initials: G
authors.lastname: Du
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
mesh_terms: D000222:Adaptation, Physiological; D001483:Base Sequence; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D019344:Lactic Acid / Q000096:biosynthesis*; D007780:Lacticaseibacillus casei / Q000378:metabolism*; D013294:Lactococcus lactis / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological
chemical_list: D017931:DNA Primers; D019344:Lactic Acid; D012965:Sodium Chloride
keywords: Lactic acid production; Lactococcus lactis; RecO; Stress tolerance